Sweetener and preparation method thereof

The invention discloses a sweetener and a preparation method thereof. The sweetener contains, based on dry weight, 20-98% of total mogroside from grosvenor momordica fruit, wherein mogroside V accounts for 5-80%. When the sweetener completely dissolves in water and has a same sweetness as a 5% (w/w) cane sugar aqueous solution under a same condition, the sweetener aqueous solution has a 210nm absorbance of 1.2-1.4. The preparation method of the sweetener comprises steps of: adding water and pectase into grosvenor momordica fruit for extraction, extracting injecting liquid, loading on a macroporous resin column and collecting an ethanol eluate; flowing an eluate through a neutral alumina column, collecting an effluent, recovering the ethanol, concentrating and drying. Compared with a prior art, the sweetener in the above limited scope is in light yellow or white, and has no traditional Chinese medicine taste or bitter taste of grosvenor momordica fruit; and the preparation method is simple, at low costs and easy for industrialized production.